How to display a matrix in the Matplotlib annotations

Question

I\'m trying to plot a matrix using the annotations of a Matplotlib-Plot. Is this even possible?

Tried around with the most basic example, which all break the plot:

Answer 1

MatPlotLib uses its own typesetting framework (MathText). Your system's LaTeX rendering can be enabled by, rcParams['text.usetex'] = True.

The other problem that you have is a double-quoted multi-line string. This isn't really allowed without using a \, and that is difficult to manage with your existing \\.

Try this:

from matplotlib import rcParams

rcParams['text.usetex'] = True

ax.annotate(
    r"$ \begin{array}{ccc} a & b & c \\ d & e & f \\ g & h & i \end{array} $",
    (0.25, 0.25),
    textcoords='axes fraction', size=20)

Here I have used the array environment, rather than matrix because I don't think the latter is a LaTeX built-in. If you really want matrix--or other amsmath items--you can add the amsmath package to the MatPlotLib LaTeX preamble:

rcParams['text.latex.preamble'] = r'\usepackage{amsmath}'

Then the matrix environment will work,

ax.annotate(
    r"$ \begin{matrix} a & b & c \\ d & e & f \\ g & h & i \end{matrix} $",
    (0.25, 0.25),
    textcoords='axes fraction', size=20)